Tadic was frustrated with Koeman's decision to drop him for the Saints' match against FC Midtjylland in the Europa League and requested a meeting with his manager.
During that conversation, Koeman told Tadic that he was not happy with the way that the attacking midfielder was playing over the early part of the season.
However, since that frank discussion, Tadic has improved and Koeman is pleased with the way he has responded to their talks.
“I had some good discussions with Dusan in the last few weeks," Koeman said.
“He was not happy about some decisions that I took. For example he was on the bench against Midjytlland in the away game but I wasn’t happy about the performance of Dusan and of course, part of that problem, is that he was not really really fresh and he was struggling with his groin problem."
Tadic plays an important role for Southampton, and he is one of the most talented players in their squad when he is on his game.
The Serbian is a natural in possession, with Koeman tasking him with being the side's main creator.
In his first season in England, he was brilliant - providing chances for his teammates and scoring with regularity, as he helped Southampton to claim a Europa League spot.
His form hasn't been as consistently excellent this time around, but with Southampton starting to click into gear he will be hoping to raise his game soon.
The Saints are currently sat in 10th place in the Premier League table, and beat Swansea City 3-1 in their most recent fixture, with Tadic getting on the scoresheet during that contest.